This Program Project addresses a critical supramolecular system in Vascular Biology, the molecular pathways responsible for hemostasis and inflammation, thrombogenesis, thrombolysis, and immune mediated vascular inflammation, implicated as well in vascular diseases including atherosclerosis, and thought to play a meaningful role in cell adhesion, movement in embryogenesis and tissue development. The assembly of these molecular pathways on cell surfaces is a thematic issue. The central hypothesis is that the basis of important vascular diseases rests in the cell biology and molecular biology of the vascular system and the solutions rest in the structure of the proteins and their receptors. The concept that there are active stimuli for transcription, secretion, cell surface assembly and structural control of cell function are at the core of our approach to vascular diseases. Elucidation of the molecules that are responsible for initiation, propagation and the observed effect has proceed to the analysis of the structural basis of function.